Systemless root/Xposed 86.2 not very system-less

I don't understand why Android August OTA indicates "System has unexpecting content" whereas the only modifications I made since my last factory reset (two weeks ago due to encryption decrypt corruption with July OTA) were to flash systemless SuperSu and systemless Xposed 86.2 and install BusyBox to /su.

I tried once directly via System updates section and twice with Flashfire default OTA config.

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